1. Field of the Invention.
The present invention relates generally to the field of valves, and more particularly, but not by way of limitation, to a drain valve for preventing damage to an externally disposed water faucet due to low temperature conditions.
2. Brief Description of the Prior Art.
Devices known as faucets are used for controlling the flow of water from a water supply of a structure to selected locations external the structure. Generally, the faucet is secured to an external wall of the structure such that the distal end of the stem or screw spindle of the faucet is exposed, and the opposite end of the stem, which carries the valve disk for engaging a valve seat, extends through the wall of the structure. The distal end of the stem of the faucet is provided with a handle so that the relationship between the valve disk and valve seat can be altered in response to movement of the handle and to permit flow of water through the faucet.
While the structure of the faucet has generally been accepted, problems are nevertheless encountered when one permits an object, such as a hose, to remain connected to the outlet of the water faucet when low temperatures are encountered. For example, when a hose is connected to the faucet and low temperatures are encountered, residual water in the faucet may freeze resulting in a break in the waterline interior the wall structure. While it is common knowledge that such damage is likely to occur, one often forgets to disconnect the hose from the faucet.
Numerous prior art devices have been proposed for automatically draining water from a water delivery source, such as a drinking fountain, a hydrant and the like. Typical of such a prior art device is the drain-valve for a drinking fountain disclosed by Catlin (U.S. Pat. No. 1,788,449). Catlin teaches a device for attachment to the end of a spigot having a tube for normal pressurized flow of water, and a spring biased valve for engagement in a valve seat during use. When water pressure is absence, the spring forces disengagement of the valve to allow water to drain from an exposed tube.
Another typical prior art device is that disclosed in U.S. Pat. No. 1,297,001, issued O'Shields. O'Shields discloses a ball valve mounted upstream from a discharge nozzle. The valve allows the column of residue fluid in the cylindrical section of a hydrant to drain through an eduction pipe during nonuse.
Buckler (U.S. Pat. No. 1,457,422) teaches a drain valve disposed on a fire hydrant to prevent freezing thereof; and Reniff (U.S. Pat. No. 1,127,282) discloses a drainage valve in a railroad-car steam line to prevent freezing of collected water.
Numerous other devices have been proposed by the prior art in an effort to prevent residual water from freezing in a valve, especially when the valve is inadvertently attached to an object, such as a hose. However, a need has long remained for an improved faucet drain apparatus which will insure that the residual water in the faucet will be removed, and which can be built into the structure, or attached to an existing faucet. It is to such a device that the present invention is directed.